Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, openWorldHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context about how costs are computed (one copy of each collector number at cheapest printing, USD, same figure as set page), that the master set total is labeled separately, and that companion sets are catalogued separately with their own totals.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the usage scenario in the first sentence and then details the return contents before closing with the prerequisite. It is longer than average but every sentence contributes relevant scope or output detail for a complex set-pricing tool. It could be tightened slightly, but it is well structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given that an output schema exists, the description need not explain return values, yet it provides enough context to understand what the tool returns and when to call it. Annotations cover the safety profile, the schema covers the parameter, and the description covers scope, usage, and output composition. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the single parameter is already fully documented in the schema. The description repeats the same information ('Needs a group_id from search_cards') without adding syntax, format, or source details beyond the schema. Baseline 3 is appropriate when the schema carries the parameter semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: it returns set-level pricing aggregates including cost to complete, master set total, top singles, sealed products, and companion set totals. This clearly distinguishes it from siblings like card_price (single-card pricing) and most_valuable (likely cross-set rankings) by scoping everything to one set.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly says to use this when the user asks what a set is worth, what it costs to complete, or which cards in one set are most valuable. It also gives the prerequisite (group_id from search_cards). It does not name alternative tools or conditions when not to use it, which keeps it from a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.